Generating Random Number between two numbers in JavaScript

In this tutorial, we are going to learn about how to generate a random number between two numbers inclusively in JavaScript.

We can use Math.floor and Math.random() method to generate a random number between two numbers where both minimum and the maximum value is included in the output.

This below example shows you a function that is used to generate a random number based on the arguments we passed to it.

function randomNumber(min, max) { // min and max included
  return Math.floor(Math.random() * (max - min+1)+min);
}

console.log(randomNumber(20, 25));

In the above code, we have passed 20,25 as an argument to randomNumber function so that we will get a random number between 20 to 25.

Explanation

Let’s see how our randomNumber function works.

Math.random()*(max-min+1)+min;

First, we are multiplying Math.random() method with (max-min+1)+min values, so that we’ll get a random floating-point number between the max and min values.

Now we need to convert a floating-number to number or integer by passing it as an argument to the Math.floor() method.

The Math.floor() methods rounds the value to its nearest integer.

Math.floor(23.455); // 23

// Math.floor(Math.random()*(max-min+1)+min);

// Math.floor(Math.random()*(25-20+1)+20);


function randomNumber(min, max) {
  return Math.floor(Math.random() * (max - min+1)+min);
}